Ummm frank, yes I do fly above FL290. I'm sorry I forgot your PPrune post count is directly related to the performance of your aircraft...
I dont know what my
company pays, but they pay and being ADS-B identified has helped me out more than once.
To please the average owner I cant see it helping with typical private flying situations. I have no idea on the on going costs but I'm assuming its not cheap. Until it does become affordable and every bug smasher is fitted its kind of pointless. A basic TCAS unit would be better value.